Cyperus esculentus milk and preparation method thereof

Abstract

The invention discloses mandulapalka milk and a preparation method thereof, and belongs to the technical field of beverage processing. According to the technical scheme provided by the invention, the preparation method of the degreased cyperus esculentus milk enzymolysis beverage comprises the following steps: adding high-temperature amylase into a degreased cyperus esculentus meal aqueous solution for enzymolysis for 1 hour, and then adding alkaline protease and flavourzyme for enzymolysis for 1 hour to obtain an enzymolysis solution; and finally, emulsifying residual starch and dextrin in the enzymatic hydrolysate by using soybean protein isolate and corn oil, and homogenizing by using a high-pressure homogenizer to obtain the cyperus esculentus beverage. According to the method, a multi-enzymolysis technology is adopted, the enzymolysis speed can be increased, the taste can be improved, a double-enzymolysis method is adopted, the enzymolysis time is shortened, starch is subjected to enzymolysis more sufficiently, and the flavor is improved. The defatted cyperus esculentus beverage prepared by the method disclosed by the invention is appropriate in sweetness, silky in mouth, mellow and strong in fragrance and unique in flavor, and is a healthy and mellow leisure beverage.

Description

Technical Field

[0001] The present invention relates to a Cyperus esculentus milk and a preparation method thereof, belonging to the technical field of beverage processing. Background Art

[0002] Cyperus esculentus var. sativus, also known as iron water chestnut, Chinese tiger nut, and Cyperus esculentus, is a perennial herbaceous plant of the genus Cyperus in the family Cyperaceae. Cyperus esculentus has various physiological functions, including regulating blood sugar, reducing cholesterol, preventing constipation, antioxidation, and enhancing immunity. It is rich in dietary fiber and plant protein, which can effectively regulate blood sugar levels and has a certain adjuvant therapeutic effect on diabetic patients. At the same time, the dietary fiber and plant protein in Cyperus esculentus can also help reduce the cholesterol level in the body, which is beneficial to cardiovascular health. In addition, the dietary fiber in Cyperus esculentus can increase intestinal peristalsis, promote defecation, and prevent constipation problems. Cyperus esculentus is rich in vitamin C and vitamin E, which has strong antioxidant effects, helps resist the invasion of free radicals, and delays aging. Cyperus esculentus also contains rich vitamins and minerals, which can enhance the body's immunity and improve the ability to resist diseases.

[0003] For example, the patent with publication number CN117137058A discloses a method for preparing a Cyperus esculentus extract beverage using Cyperus esculentus as a raw material, which includes steps such as material selection, cleaning, soaking, peeling, pulping, boiling, enzymatic hydrolysis, enzymatic hydrolysis, and modulation. The patent with publication number CN102224960B discloses a method for preparing a Cyperus esculentus beverage using Cyperus esculentus as a raw material, which includes steps such as crushing and sieving, baking, dissolving and pulping, enzymatic hydrolysis, filtering to obtain Cyperus esculentus juice, and then using this juice as a base material, and going through processes such as blending, homogenization, and microwave sterilization. The patent with publication number CN1313056 discloses a method for preparing a milky white Cyperus esculentus plant protein beverage using Cyperus esculentus as a raw material, which includes steps such as peeling, soaking and grinding, enzymatic hydrolysis, filtering to obtain Cyperus esculentus juice, using this juice as a base material, and going through processes such as blending, homogenization, and sterilization.

[0004] However, due to the rich starch content in defatted Cyperus esculentus meal, during the preparation of beverages, due to the presence of excessive starch, which is completely different from the conventional emulsion system (oil and protein), the stability of the defatted Cyperus esculentus milk is poor, greatly affecting the taste and acceptance during drinking, thus restricting the commercialization of Cyperus esculentus meal and the development of its related beverages. How to stabilize the starch in defatted Cyperus esculentus beverages is an urgent problem to be solved. Summary of the Invention

[0005] In view of the above problems, the present invention provides a preparation method for a defatted Cyperus esculentus beverage. The defatted Cyperus esculentus milk beverage obtained based on multi-enzymatic hydrolysis technology and an emulsifying and stabilizing system has a short enzymatic hydrolysis time, a sweet taste, a milky white color, a stable defatted Cyperus esculentus milk system, and a unique flavor.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The technical solution provided by the present invention is a preparation method of a degreased Cyperus esculentus milk enzymolysis beverage. Add high-temperature amylase to the aqueous solution of degreased Cyperus esculentus meal and enzymolyze for 1 h, then add alkaline protease and flavor protease and enzymolyze for 1 h to obtain an enzymolysis solution. Finally, use soy protein isolate and corn oil to emulsify the remaining starch in the enzymolysis solution, and then perform homogenization treatment through a high-pressure homogenizer to obtain a Cyperus esculentus beverage.

[0008] The present invention provides a degreased Cyperus esculentus beverage, and the degreased Cyperus esculentus beverage is prepared by the following method:

[0009] (1) Mix degreased Cyperus esculentus meal with water and beat to obtain a slurry;

[0010] (2) After enzymolyzing the obtained slurry, add vegetable protein and oil, and then perform blending by shearing to obtain a liquid material;

[0011] (3) Sterilize the obtained liquid material to obtain a degreased Cyperus esculentus beverage;

[0012] The vegetable protein includes but is not limited to: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes but is not limited to: corn oil, soybean oil, peanut oil, rapeseed oil.

[0013] In an embodiment of the present invention, in step (1), the mass fraction of starch in the slurry is: 4.75 - 5.75%; preferably, the mass fraction of starch in the slurry is: 5%;

[0014] In an embodiment of the present invention, in step (2), the enzymolysis is as follows: add 0.1 - 0.5‰ of high-temperature amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymolysis conditions are: temperature: 75 - 95°C, enzymolysis time: 10 - 60 min; further, the enzymolysis conditions are: temperature: 85°C, enzymolysis time: 30 min;

[0015] In an embodiment of the present invention, in step (2), the enzymolysis is two-stage enzymolysis. Among them, the first-stage enzymolysis is to add 0.1 - 0.5‰ of high-temperature amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymolysis conditions are: temperature: 75 - 95°C, enzymolysis time: 10 - 60 min; further, the enzymolysis conditions are: temperature: 80°C, enzymolysis time: 30 min;

[0016] The two-stage enzymatic hydrolysis is as follows: into the enzymatic hydrolysate after the first-stage enzymatic hydrolysis, add alkaline protease at 0.3 - 0.7‰ of the raw material mass and flavor protease at 0.8 - 1.2‰ of the raw material mass. The enzymatic hydrolysis conditions are: temperature: 45 - 55°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 50°C, enzymatic hydrolysis time: 30 min.

[0017] In one embodiment of the present invention, in step (2), the plant protein is soy protein isolate and the oil is corn oil;

[0018] In one embodiment of the present invention, the addition amount of the soy protein isolate is 0.5 - 4.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0 - 3.5% based on the mass of the feed liquid.

[0019] In one embodiment of the present invention, the addition amount of the soy protein isolate is 1.5% based on the mass of the feed liquid, and the addition amount of the corn oil is 1% based on the mass of the feed liquid;

[0020] Or the addition amount of the soy protein isolate is 3% based on the mass of the feed liquid, and the addition amount of the corn oil is 3.5% based on the mass of the feed liquid.

[0021] The present invention provides a preparation method of a defatted Cyperus esculentus L. beverage. The preparation method is as follows:

[0022] (1) Mix the defatted Cyperus esculentus L. meal with water and beat to obtain a slurry;

[0023] (2) After subjecting the obtained slurry to enzymatic hydrolysis, add plant protein and oil, and then adjust the mixture by shearing to obtain a feed liquid;

[0024] (3) Sterilize the obtained feed liquid to obtain the defatted Cyperus esculentus L. beverage;

[0025] The plant protein includes but is not limited to: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes but is not limited to: corn oil, soybean oil, peanut oil, rapeseed oil.

[0026] In one embodiment of the present invention, in step (1), the mass fraction of starch in the slurry is 4.75 - 5.75%; preferably, the mass fraction of starch in the slurry is 5%;

[0027] In one embodiment of the present invention, in step (2), the enzymatic hydrolysis is as follows: into the slurry prepared in step (1), add α - thermostable amylase at 0.1 - 0.5‰ of the raw material mass. The enzymatic hydrolysis conditions are: temperature: 75 - 95°C, enzymatic hydrolysis time: 10 - 60 min;

[0028] In one embodiment of the present invention, the enzymatic hydrolysis conditions are: temperature: 85°C, enzymatic hydrolysis time: 60 min.

[0029] In one embodiment of the present invention, in step (2), the enzymatic hydrolysis is two-stage enzymatic hydrolysis. Among them, the first-stage enzymatic hydrolysis is to add 0.1-0.5‰ of high-temperature amylase based on the mass of the raw material to the slurry prepared in step (1). The enzymatic hydrolysis conditions are: temperature: 75-95°C, enzymatic hydrolysis time: 10-60 min;

[0030] In one embodiment of the present invention, the enzymatic hydrolysis conditions are: temperature: 85°C, enzymatic hydrolysis time: 60 min;

[0031] The second-stage enzymatic hydrolysis is to add 0.3-0.7‰ of alkaline protease and 0.8-1.2‰ of flavor protease based on the mass of the raw material to the enzymatic hydrolysate after the first-stage enzymatic hydrolysis. The enzymatic hydrolysis conditions are: temperature: 45-55°C, enzymatic hydrolysis time: 10-60 min;

[0032] In one embodiment of the present invention, the enzymatic hydrolysis conditions are: temperature: 50°C, enzymatic hydrolysis time: 60 min.

[0033] In one embodiment of the present invention, in step (2), the plant protein is soy protein isolate, and the oil is corn oil;

[0034] In one embodiment of the present invention, the addition amount of the soy protein isolate is 0.5-4.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0-3.5% based on the mass of the feed liquid.

[0035] In one embodiment of the present invention, the addition amount of the soy protein isolate is 1.5% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0% based on the mass of the feed liquid;

[0036] Or the addition amount of the soy protein isolate is 3.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 3.5% based on the mass of the feed liquid.

[0037] The present invention also provides the application of the above preparation method in the preparation of defatted Cyperus esculentus L. beverages.

[0038] The present invention also provides a method for improving the stability of a defatted Cyperus esculentus L. beverage system with a high starch content. The method is to mix defatted Cyperus esculentus L. meal with water, beat into a slurry, perform enzymatic hydrolysis, then add plant protein and oil, and perform blending by shearing to obtain a feed liquid; sterilize the obtained feed liquid to obtain a defatted Cyperus esculentus L. beverage; the plant protein includes: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes: corn oil, soybean oil, peanut oil, rapeseed oil;

[0039] Preferably, the enzymatic hydrolysis is carried out by adding 0.1 - 0.5‰ of α - high - temperature amylase based on the mass of the raw material to the slurry. The enzymatic hydrolysis conditions are: temperature: 75 - 95°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 85°C, enzymatic hydrolysis time: 30 min;

[0040] Preferably, the enzymatic hydrolysis is two - stage enzymatic hydrolysis. Among them, the first - stage enzymatic hydrolysis is carried out by adding 0.1 - 0.5‰ of high - temperature amylase based on the mass of the raw material to the slurry. The enzymatic hydrolysis conditions are: temperature: 75 - 95°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 80°C, enzymatic hydrolysis time: 30 min; the second - stage enzymatic hydrolysis is carried out by adding 0.3 - 0.7‰ of alkaline protease and 0.8 - 1.2‰ of flavor protease based on the mass of the raw material to the enzymatic hydrolysate after the first - stage enzymatic hydrolysis. The enzymatic hydrolysis conditions are: temperature: 45 - 55°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 50°C, enzymatic hydrolysis time: 30 min;

[0041] Preferably, the plant protein is soy protein isolate, and the oil is corn oil; the addition amount of the soy protein isolate is 0.5 - 4.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0 - 3.5% based on the mass of the feed liquid.

[0042] Beneficial effects

[0043] (1) The method of the present invention uses high - temperature amylase to hydrolyze amylose and amylopectin in defatted Cyperus esculentus meal, specifically acting on α - 1,4 - glycosidic bonds, effectively reducing the precipitation of starch in the feed liquid, and significantly improving the product stability.

[0044] (2) The alkaline protease and flavor protease added in the method of the present invention more significantly improve the sensory quality of the product.

[0045] (3) The protein and oil added in the method of the present invention further improve the product stability and enhance the sensory characteristics of the product at the same time.

[0046] (4) The method of the present invention adopts a staged compound enzymatic hydrolysis technology, realizing the full degradation of starch and promoting the release of flavor substances. The defatted Cyperus esculentus beverage prepared by the method of the present invention has a suitable sweetness, a smooth taste in the mouth, a strong and mellow fragrance, and a unique flavor, and is a healthy and mellow leisure beverage. Specific embodiments

[0047] In order to make the purpose, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in combination with specific embodiments.

[0048] The Cyperus esculentus involved in the following examples was purchased from Ningxia. The Cyperus esculentus meal is a commercially available product and can be directly purchased or prepared according to conventional methods. Among them, the preparation method of the Cyperus esculentus meal is as follows: After crushing, baking (120 - 130 °C, for 20 - 30 minutes), pressing, and filtering, the Cyperus esculentus meal is obtained, with an oil content of 3%. The Cyperus esculentus meal of the present invention was purchased from Jilin Green Doctor Ecological Technology Development Co., Ltd.

[0049] The medium-temperature amylase involved in the following examples was purchased from Novozymes (China) Biotechnology Co., Ltd., Tianjin, with the model number BAN480L; among them, the enzyme activity of this product is 480 KNU / g. The α-thermostable amylase involved was purchased from Novozymes (China) Biotechnology Co., Ltd., Tianjin, with the model number Termanyl SC DS, and the enzyme activity of this product is 117,000 U / g.

[0050] The alkaline protease involved in the following examples was purchased from Wuxi Youpuke Biotechnology Co., Ltd., with the model number Pr6L. Among them, the enzyme activity of this product is: 240,000 U / g. The flavor protease involved in the following examples was purchased from Novozymes (China) Biotechnology Co., Ltd., Tianjin, with the model number Flavourzyme 500MG. Among them, the enzyme activity of this product is: 500 LAPU / g.

[0051] The soy protein isolate involved in the following examples was purchased from Shandong Linyi Shansong Bioproducts Co., Ltd., with a protein content of ≥90%. The corn oil involved in the following examples was purchased from Shanghai Yihai Kerry Food Marketing Co., Ltd.

[0052] The detection methods involved in the following examples are as follows:

[0053] Detection of potential

[0054] Use a BT-Zeta100 potential particle size analyzer for determination

[0055] 1. Turn on the switch at the rear right of the instrument and the computer host;

[0056] 2. Open the Baxter ZETA potential and nano particle size analysis system V2.0 → click File → New → sop → input sample parameters → temperature 25 °C, equilibrium time 60 s → select the corresponding sample cell type;

[0057] 3. Add the sample to the sample cell. Generally, the sample needs to be centrifuged or diluted (generally 100 - 500 times), with an addition amount of 1 - 1.5 mL. Insert it into the sample slot and cover the instrument lid;

[0058] 4. Start the measurement, and note that it needs to be clicked twice in total;

[0059] Detection of stability coefficient

[0060] Shake the prepared Cyperus esculentus milk well, accurately weigh 10 g of the sample, centrifuge at 3500 r / min for 15 min, then aspirate 0.5 mL of the whey phase in the middle of the milk, dilute it with pure water at a volume ratio of 1:15, and measure the absorbance at its maximum absorption wavelength. After shaking well, aspirate the emulsion and dilute it in the same method as above, and measure the absorbance. Calculate the stability coefficient through the following formula. The larger the stability coefficient, the better the stability.

[0061]

[0062] In the formula: A0 is the absorbance at the maximum absorption wavelength of the milk after shaking well; A1 is the absorbance at the maximum absorption wavelength of the whey phase after centrifugation.

[0063] Detection of centrifugal precipitation rate

[0064] Shake the prepared Cyperus esculentus milk well, accurately weigh 10 g of the sample, centrifuge at 3500 r / min for 15 min, pour out the supernatant, and weigh the mass of the precipitate remaining at the bottom of the centrifuge tube. Conduct 3 parallel tests, and calculate the centrifugal precipitation rate through the following formula. The smaller the centrifugal precipitation rate, the better the stability.

[0065]

[0066] In the formula: m0 is the mass of the sample before centrifugation, g; m1 is the mass of the precipitate after centrifugation, g.

[0067] Detection of emulsification stability index

[0068] Detection of emulsification stability index (ESI). Take 5 mL of soybean oil and mix it with 15 mL of Cyperus esculentus milk, use high-speed shear emulsification to shear and emulsify it at a rotation speed of 18000 r / min for 2 min. After emulsification, pour it into a 50 mL beaker for standby. At 0 min and 30 min respectively, take 20 μL of the sample at the bottom of the emulsified beaker and mix it evenly with 5 mL of 0.1% sodium dodecyl sulfate solution, and measure its absorbance at 500 nm with a UV spectrophotometer. Conduct 3 parallel tests for each sample, and take the average value for calculation. The emulsification stability index can be calculated through the following formula:

[0069]

[0070] In the formula, A0 is the absorbance measured at 0 min, A 30 is the absorbance measured at 30 min, and Δt is the time difference between the two absorbance measurements.

[0071] Detection of DE value

[0072] The reducing sugar was determined by the direct titration method in the first method of GB5009.7-2016, and the DE value was calculated by the formula.

[0073] Example 1: A preparation method of defatted Cyperus esculentus L. beverage

[0074] Specifically, it includes the following steps:

[0075] After screening, the defatted Cyperus esculentus L. meal was mixed with water at a ratio of 1:3 to make the starch content in the mixture 5%, and then it was pulped with a wall-breaking pulper and filtered; defatted Cyperus esculentus L. milk was obtained.

[0076] The stability of the obtained defatted Cyperus esculentus L. milk was detected. The results showed that the potential was -12.77 mV, the stability coefficient was 22.116%, the centrifugal sedimentation rate was 40.235%, the stability was extremely poor, and there was a visible three-layer stratification.

[0077] Example 2: A preparation method of defatted Cyperus esculentus L. beverage

[0078] In order to improve the stability of defatted Cyperus esculentus L. milk, enzymatic hydrolysis was carried out. Among them, the two-stage enzymatic hydrolysis was to improve flavor substances. Specifically, it includes the following steps:

[0079] 1. Preparation of defatted Cyperus esculentus L. milk

[0080] (1) Raw material pretreatment:

[0081] After screening, the defatted Cyperus esculentus L. meal was mixed with water at a ratio of 1:3 to make the starch content in the mixture 5%, and then it was pulped with a wall-breaking pulper;

[0082] (2) First-stage enzymatic hydrolysis: The liquid material prepared in step (1) was added with 0.1‰ α-thermostable amylase based on the mass of the raw material, and enzymatically hydrolyzed at 85°C for 0.5 h;

[0083] (3) Second-stage enzymatic hydrolysis: The liquid material treated in step (2) was added with 0.5‰ alkaline protease (the added enzyme activity was: 240,000 U / g) and 1‰ flavor protease (the added enzyme activity was: 500 LAPU / g), enzymatically hydrolyzed at 50°C for 1 h, and then inactivated at 95°C for 30 min; an enzymatic hydrolysate was obtained;

[0084] (4) Filtration: The enzymatic hydrolysate prepared in step (3) was filtered through a 200-mesh sieve; a defatted Cyperus esculentus L. beverage was obtained.

[0085] The performance of the obtained beverage was detected. The results showed that the potential was -20.15 mV, the stability coefficient was 44.114%, and the centrifugal sedimentation rate was 22.058%.

[0086] 2. Optimize the conditions to improve the stability of defatted Cyperus esculentus L. milk

[0087] Specifically, it is the same as step 1, except that the enzymatic hydrolysis conditions in step (2) are adjusted as follows: add 0.2‰ of α-thermostable amylase based on the mass of the raw materials, and perform enzymatic hydrolysis at 85°C for 1 h.

[0088] The results show that the potential is -26.15 mV, the stability coefficient is 72.236%, and the centrifugal precipitation rate is 9.15%.

[0089] It can be seen that although the stability is improved, there are two visible layers of stratification. It needs to be carefully observed in the short term, and the stratification becomes obvious after long-term placement.

[0090] Example 3: A preparation method of defatted Cyperus esculentus L. beverage

[0091] In order to further improve the stability of Cyperus esculentus L. milk, proteins and oils were added on the basis of enzymatic hydrolysis, and the specific steps are as follows:

[0092] (1) Pretreatment of raw materials:

[0093] After screening, the defatted Cyperus esculentus L. meal is mixed with water at a ratio of 1:3 to make the starch content in the mixture 5%, and then it is pulped using a wall-breaking pulper.

[0094] (2) First-stage enzymatic hydrolysis: Add 0.2‰ of α-thermostable amylase based on the mass of the raw materials to the liquid material prepared in step (1), and perform enzymatic hydrolysis at 85°C for different times: 10 min, 20 min, 30 min, 40 min, 50 min, 60 min (specifically shown in Tables 1 - 8).

[0095] (3) Second-stage enzymatic hydrolysis: Add 0.5‰ of alkaline protease and 1‰ of flavor protease based on the mass of the raw materials to the liquid material prepared in step (2), perform enzymatic hydrolysis at 50°C for 1 h, and inactivate the enzyme at 95°C for 30 min.

[0096] (4) Filtration: Filter the enzymatic hydrolysate prepared in step (3) through a 200-mesh sieve.

[0097] (5) Blending: Add different contents of soy protein isolate and corn oil (the addition amount of corn oil is 1% or 3.5% of the mass of the liquid material, and the addition amount of soy protein isolate is 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0% of the mass of the liquid material, specifically shown in Tables 1 - 8) to the enzymatic hydrolysate prepared in step (4), and perform blending through high-speed shearing. The shearing time is 15 min, and the rotation speed is 15000 r / min.

[0098] (6) Sterilization: Heat-treat the liquid material prepared in step (5) by ultra-high temperature instantaneous sterilization at 138°C for 5 s to remove pathogenic bacteria in the product.

[0099] (7) Canning: The liquid material prepared in step (6) is rapidly cooled for aseptic canning.

[0100] (8) Secondary sterilization: The canned tiger nut milk in step (7) is sterilized at high temperature and high pressure of 105 °C for 15 min.

[0101] Different tiger nut milks are respectively prepared.

[0102] Example 4: Experimental results

[0103] The zeta potential, stability coefficient, centrifugal precipitation rate, emulsion stability, and DE value of the tiger nut milk obtained by using the method of Example 3, that is, different enzymolysis times and different content ratios of protein and corn oil, are respectively detected. The results are as follows:

[0104] 1. Influence of the zeta potential of tiger nut milk obtained with different enzymolysis times and different content ratios of protein and corn oil

[0105] Table 1 Zeta potential (mV) of tiger nut milk when the corn oil addition is 1%

[0106]

[0107] Table 2 Zeta potential (mV) of tiger nut milk when the corn oil addition is 3.5%

[0108]

[0109] The results show that:

[0110] Since the zeta potential of the emulsion is greater than 25 or less than -25, the emulsion can be considered relatively stable, and within this range, the larger the zeta potential value, the more stable it is. The results show that:

[0111] Under the condition of the same enzymolysis time with an oil content of 1%, the zeta potential shows a trend of first decreasing and then increasing as the protein content increases; since it is a negative zeta potential, this indicates that the emulsion stability first increases and then decreases as the protein content increases.

[0112] Under the condition of the same enzymolysis time with an oil content of 3.5%, the zeta potential shows a trend of first decreasing and then increasing as the protein content increases; since it is a negative zeta potential, this indicates that the emulsion stability first increases and then decreases as the protein content increases.

[0113] Under the condition of the same addition amount of oil and protein, the zeta potential shows a trend of first increasing and then decreasing as the enzymolysis time increases; since it is a negative zeta potential, this indicates that the emulsion stability first decreases and then increases as the enzymolysis time increases.

[0114] 2. Effects of different enzymatic hydrolysis times and different ratios of protein and corn oil contents on the stability coefficient and centrifugal precipitation rate of Cyperus esculentus milk

[0115] Table 3 Stability coefficient (%) of Cyperus esculentus milk when the corn oil addition is 1%

[0116]

[0117] Table 4 Stability coefficient (%) of Cyperus esculentus milk when the corn oil addition is 3.5%

[0118]

[0119] Table 5 Centrifugal precipitation rate (%) of Cyperus esculentus milk when the corn oil addition is 1%

[0120]

[0121]

[0122] Table 6 Centrifugal precipitation rate (%) of Cyperus esculentus milk when the corn oil addition is 3.5%

[0123]

[0124] The results show that:

[0125] As can be seen from Table 3 and Table 5, at the same enzymatic hydrolysis time with an oil addition of 1% (horizontal comparison in the table), when the protein content increases from 0.5% to 1.5%, the stability coefficient of Cyperus esculentus milk shows an upward trend. It can be seen that the protein loading inside the emulsion gradually increases, making the emulsion droplets stably exist in the emulsion. When the protein content increases from 1.5% to 2.5%, the protein loading inside the emulsion is excessive, causing some proteins not to participate in emulsification and unable to stably exist in the emulsion. Therefore, the stability coefficient shows a downward trend.

[0126] Referring to relevant literature, the larger the stability coefficient, the lower the centrifugal precipitation rate of the emulsion and the more stable the system. Conversely, the smaller the stability coefficient, the higher the centrifugal precipitation rate and the worse the stability.

[0127] As can be seen from Table 4 and Table 6, at the same enzymatic hydrolysis time with an oil addition of 3.5% (horizontal comparison in the table), when the protein content increases from 1.5% to 3.0%, the stability coefficient of Cyperus esculentus milk shows an upward trend. It can be seen that the protein loading inside the emulsion gradually increases, making the emulsion droplets stably exist in the emulsion. When the protein content increases from 3.0% to 4%, the protein loading inside the emulsion is excessive, causing some proteins not to participate in emulsification and unable to stably exist in the emulsion. Therefore, the stability coefficient shows a downward trend.

[0128] As can be seen from the above four tables, when the addition amounts of oil and protein are the same (vertical comparison), as the enzymolysis time increases from 10 min to 30 min, the stability coefficient of tiger nut milk shows a downward trend. It can be seen that in the early stage of enzymolysis, the size of dextrin is relatively large. When the size of starch dextrin is relatively large, it is easy to induce depletion flocculation between emulsion droplets, resulting in a decrease in the stability of the emulsion system; when the enzymolysis time increases from 40 min to 60 min, the size of dextrin decreases with the prolongation of enzymolysis time. The dextrin emulsion system with a small size presents a stable state of small droplet dispersion and has good stability.

[0129] 3. Influence of enzymolysis time, different protein and corn oil content ratios on the emulsifying stability of tiger nut milk

[0130] Table 7 Emulsifying stability index of tiger nut milk when the addition amount of corn oil is 1% (m 2 / g)

[0131]

[0132] Table 8 Emulsifying stability index of tiger nut milk when the addition amount of corn oil is 3.5% (m 2 / g)

[0133]

[0134] The results show that:

[0135] As can be seen from Table 7, at the same enzymolysis time when the addition amount of oil is 1% (horizontal comparison in the table), as the protein content increases from 0.5% to 1.5%, the emulsifying stability of tiger nut milk shows an upward trend. It can be seen that the unfolding rate of proteins inside the emulsion is relatively fast and the loading amount gradually increases, enabling the emulsion droplets to stably exist in the emulsion; when the protein content increases from 1.5% to 2.5%, too high a concentration is not conducive to the formation of the emulsion. Too high a protein concentration will limit the subsequent unfolding of these adjacent molecules in the adsorption layer through the steric hindrance and electrostatic repulsion at the oil-water interface, thereby reducing the unfolding rate of the proteins in the interfacial layer and further reducing the emulsifying stability index.

[0136] As can be seen from Table 8, at the same enzymatic hydrolysis time with an oil addition of 3.5% (horizontal comparison in the table), when the protein content increased from 1.5% to 3.0%, the emulsion stability of tiger nut milk showed an upward trend. It can be seen that the protein unfolding rate inside the emulsion was relatively fast, and the loading amount gradually increased, enabling the emulsion droplets to stably exist in the emulsion. When the protein content increased from 3.0% to 4.0%, too high a concentration was not conducive to the formation of the emulsion. The excessively high protein concentration would limit the subsequent unfolding of these adjacent molecules in the adsorption layer through the steric hindrance and electrostatic repulsion at the oil-water interface, thereby reducing the protein unfolding rate in the interfacial layer and further reducing the emulsion stability index.

[0137] (4) On the basis of not adding soy protein isolate and corn oil, the influence of the DE value of tiger nut milk obtained with different content ratios of enzymatic hydrolysis time was detected.

[0138] Table 9 DE values of aqueous solutions at different enzymatic hydrolysis times

[0139]

[0140] The results showed that:

[0141] The reducing sugar and DE value in the emulsion showed a trend of first increasing and then leveling off with the enzymatic hydrolysis time; starch was enzymatically hydrolyzed into dextrin by amylase, and at the same time, the size of dextrin decreased with the increase of enzymatic hydrolysis time; therefore, the DE value increased with the increase of enzymatic hydrolysis time before 45 min, and after 45 min, although the size of dextrin was still decreasing, the DE value no longer increased but leveled off.

[0142] 4. On the basis of not adding soy protein isolate and corn oil, by comparing the addition of 1‰ flavor protease and 0.5‰ alkaline protease with the non-addition of flavor protease and alkaline protease, the influence of protease on the flavor of tiger nut milk was detected.

[0143] Table 10 Influence of compound protease on the content of flavor amino acids (mg / mL)

[0144]

[0145] The results showed that:

[0146] Free amino acids are divided into essential amino acids (EAAs: including Thr, Arg, Val, Met, Phe, Ile, Leu, and Lys), umami amino acids (UAAs: including Glu, Asp, and Lys), sweet amino acids (SAAs: including His, Thr, Ser, Gly, Ala, and Pro), and aromatic amino acids (AAAs: including Tyr, Cys, and Phe). By comparing the two, the contents of asp and lys in umami amino acids increase, all sweet amino acids increase, and the contents of cys and phe in aromatic amino acids increase. This results in a significant improvement in flavor.

[0147] 5. On the basis of not adding soy protein isolate and corn oil, compare the addition of 1‰ flavor protease and 0.5‰ alkaline protease with the non-addition of flavor protease and alkaline protease, and detect the effect of protease on the stability of tiger nut milk.

[0148] Table 11 Effect of compound protease on the centrifugal stability (%) of tiger nut milk

[0149]

[0150] Table 12 Effect of compound protease on the stability coefficient (%) of tiger nut milk

[0151]

[0152]

[0153] Table 13 Effect of compound protease on the potential (mV) of tiger nut milk

[0154]

[0155] The results show that:

[0156] In the 14-day stability test, when comparing the addition of 1‰ flavor protease and 0.5‰ alkaline protease with the non-addition of protease, the stabilities of the two are close at the same time and the stability trends are similar. Therefore, as shown in Tables 10 to 13, flavor protease and alkaline protease only increase the flavor of tiger nut milk and do not affect the stability.

[0157] In summary:

[0158] When the starch content is 5%, under the action of amylase, the DE value of tiger nut milk is 13.314 - 18.214, and when the oil content is 1%, the addition amount of plant protein is preferably 1% - 2%. When the starch content is 5%, under the action of amylase, the DE value of tiger nut milk is 24.050 - 25.260, and when the oil content is 1%, the addition amount of plant protein is preferably 1% - 2.5%; that is: when the oil content is 1%, the addition amount of plant protein is 1% - 2.5%.

[0159] When the starch content is 5%, under the action of amylase, the DE value of Cyperus esculentus milk is 18.214, and when the oil content is 3.5%, the addition amount of plant protein is preferably 2% - 4%. When the starch content is 5%, under the action of amylase, the DE value of Cyperus esculentus milk is 24.050 - 25.260, and when the oil content is 3.5%, the addition amount of plant protein is preferably 2.5% - 3.5%; that is: when the oil content is 3.5%, the addition amount of plant protein is 2% - 4%.

[0160] That is: when the starch content is 5%, the added amount of oil is: 1% - 3.5%, and the added amount of plant protein is: 1% - 4%.

[0161] Comparative example

[0162] Specifically the same as step 1 of Example 2, the difference is that the α - high temperature amylase is adjusted to medium temperature amylase, and the defatted Cyperus esculentus beverage is prepared according to the method of step 1.

[0163] The performance of the detected beverage shows that: the potential is -23.08 mV, the stability coefficient is 52.144%, and the centrifugal sedimentation rate is 11.252%.

[0164] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. A defatted Cyperus esculentus L. beverage, characterized in that, The defatted Cyperus esculentus L. beverage is prepared by the following method: (1) Mix defatted Cyperus esculentus L. meal with water and then beat to obtain a slurry; (2) After enzymolysis of the obtained slurry, add vegetable protein and oil, and then adjust the mixture by shearing to obtain a liquid mixture; (3) Sterilize the obtained liquid mixture to obtain the defatted Cyperus esculentus L. beverage; The vegetable protein includes: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes: corn oil, soybean oil, peanut oil, rapeseed oil.

2. The defatted Cyperus esculentus beverage according to claim 1, wherein In step (1), the mass fraction of starch in the slurry is: 4.75 - 5.75%; preferably, the mass fraction of starch in the slurry is: 5%; Preferably, in step (2), the enzymolysis is as follows: add 0.1 - 0.5‰ of α - high temperature amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymolysis conditions are: temperature: 75 - 95°C, enzymolysis time: 10 - 60 min; further preferably, the enzymolysis conditions are: temperature: 85°C, enzymolysis time: 30 min; Preferably, in step (2), the enzymolysis is two - stage enzymolysis. Among them, the first - stage enzymolysis is: add 0.1 - 0.5‰ of high temperature amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymolysis conditions are: temperature: 75 - 95°C, enzymolysis time: 10 - 60 min; further preferably, the enzymolysis conditions are: temperature: 80°C, enzymolysis time: 30 min; The second - stage enzymolysis is: add 0.3 - 0.7‰ of alkaline protease and 0.8 - 1.2‰ of flavor protease based on the mass of the raw materials to the enzymolysis solution after the first - stage enzymolysis, and the enzymolysis conditions are: temperature: 45 - 55°C, enzymolysis time: 10 - 60 min; further preferably, the enzymolysis conditions are: temperature: 50°C, enzymolysis time: 30 min.

3. The defatted Cyperus esculentus L. beverage according to claim 1 or 2, characterized in that, In step (2), the vegetable protein is soy protein isolate and the oil is corn oil; Preferably, the addition amount of the soy protein isolate is 0.5 - 4.0% based on the mass of the liquid mixture, and the addition amount of the corn oil is 1.0 - 3.5% based on the mass of the liquid mixture.

4. The defatted Cyperus esculentus L. beverage according to claim 3, wherein, The addition amount of the soy protein isolate is 1.5% based on the mass of the liquid mixture, and the addition amount of the corn oil is 1% based on the mass of the liquid mixture; Or the addition amount of the soy protein isolate is 3% based on the mass of the liquid mixture, and the addition amount of the corn oil is 3.5% based on the mass of the liquid mixture.

5. A preparation method of a defatted Cyperus esculentus beverage, characterized in that, The preparation method is as follows: (1) Mix defatted Cyperus esculentus L. meal with water and then beat to obtain a slurry; (2) After enzymolysis of the obtained slurry, add vegetable protein and oil, and then adjust the mixture by shearing to obtain a liquid mixture; (3) Sterilize the obtained liquid mixture to obtain the defatted Cyperus esculentus L. beverage; The vegetable protein includes: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes: corn oil, soybean oil, peanut oil, rapeseed oil.

6. The preparation method according to claim 5, wherein In step (1), the mass fraction of starch in the slurry is: 4.75 - 5.75%; preferably, the mass fraction of starch in the slurry is: 5%; Preferably, in step (2), the enzymatic hydrolysis is to add 0.1-0.5‰ of α-thermostable amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymatic hydrolysis conditions are: temperature: 75-95°C, enzymatic hydrolysis time: 10-60 min; Furthermore, the enzymatic hydrolysis conditions are: temperature: 85°C, enzymatic hydrolysis time: 60 min.

7. The preparation method according to claim 5 or 6, characterized in that, In step (2), the enzymatic hydrolysis is two-stage enzymatic hydrolysis. Among them, the first-stage enzymatic hydrolysis is to add 0.1-0.5‰ of thermostable amylase based on the mass of the raw materials to the slurry prepared in step (1), and the enzymatic hydrolysis conditions are: temperature: 75-95°C, enzymatic hydrolysis time: 10-60 min; Furthermore, the enzymatic hydrolysis conditions are: temperature: 85°C, enzymatic hydrolysis time: 60 min; The second-stage enzymatic hydrolysis is to add 0.3-0.7‰ of alkaline protease based on the mass of the raw materials and 0.8-1.2‰ of flavor protease based on the mass of the raw materials to the enzymatic hydrolysate after the first-stage enzymatic hydrolysis, and the enzymatic hydrolysis conditions are: temperature: 45-55°C, enzymatic hydrolysis time: 10-60 min; Furthermore, the enzymatic hydrolysis conditions are: temperature: 50°C, enzymatic hydrolysis time: 60 min.

8. According to the preparation method described in any one of claims 5 to 7, characterized in that, In step (2), the plant protein is soy protein isolate, and the oil is corn oil; Preferably, the addition amount of the soy protein isolate is 0.5-4.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0-3.5% based on the mass of the feed liquid; Preferably, the addition amount of the soy protein isolate is 1.5% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0% based on the mass of the feed liquid; or the addition amount of the soy protein isolate is 3.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 3.5% based on the mass of the feed liquid.

9. A method for enhancing the stability of a defatted Cyperus esculentus L. beverage system with high starch content, characterized in that, The method is to mix defatted Cyperus esculentus meal with water, beat it into a slurry, perform enzymatic hydrolysis, add plant protein and oil, and adjust the mixture by shearing to obtain a feed liquid; sterilize the obtained feed liquid to obtain a defatted Cyperus esculentus beverage; The plant protein includes: soy protein isolate, pea protein isolate, chickpea protein isolate; the oil includes: corn oil, soybean oil, peanut oil, rapeseed oil; Preferably, the enzymatic hydrolysis is to add 0.1-0.5‰ of α-thermostable amylase based on the mass of the raw materials to the slurry, and the enzymatic hydrolysis conditions are: temperature: 75-95°C, enzymatic hydrolysis time: 10-60 min; furthermore, the enzymatic hydrolysis conditions are temperature: 85°C, enzymatic hydrolysis time: 30 min; Preferably, the enzymatic hydrolysis is carried out in two stages. In the first stage of enzymatic hydrolysis, 0.1 - 0.5‰ of high-temperature amylase based on the mass of the raw material is added to the slurry. The enzymatic hydrolysis conditions are: temperature: 75 - 95°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 80°C, enzymatic hydrolysis time: 30 min. In the second stage of enzymatic hydrolysis, 0.3 - 0.7‰ of alkaline protease and 0.8 - 1.2‰ of flavor protease based on the mass of the raw material are added to the enzymatic hydrolysate after the first stage of enzymatic hydrolysis. The enzymatic hydrolysis conditions are: temperature: 45 - 55°C, enzymatic hydrolysis time: 10 - 60 min; further, the enzymatic hydrolysis conditions are: temperature: 50°C, enzymatic hydrolysis time: 30 min. Preferably, the plant protein is soy protein isolate and the oil is corn oil; the addition amount of the soy protein isolate is 0.5 - 4.0% based on the mass of the feed liquid, and the addition amount of the corn oil is 1.0 - 3.5% based on the mass of the feed liquid.

10. Use of the preparation method according to any one of claims 5 - 8 in the preparation of defatted Cyperus esculentus L. beverages.

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